It wasn't terrorists, but operator error that caused a train full of oil to derail and explode in the Quebec town of Lac-Mégantic in 2013, killing 47 people. Should firefighters and residents know whether trains loaded with explosive oil are routed through the heart of residential districts? Many railroads say no, claiming it is a security issue.

But on June 18, 2014, for perhaps the first time, the Federal Railroad Administration (FRA) dismissed that claim, saying that oil train routing was not sensitive security information.

The railroads are fighting back, mounting a campaign to get the states to black out the information the feds say must be disclosed. The FRA emergency order of May 9, 2014, requires the railroads to disclose routing of oil trains to the "State Emergency Response Commissions," which are required by federal law to disclose it to the public and news media.